Tóm tắt

SnO2 voltage-sensitive ceramics is a kind of ceramic with nonlinear characteristics, which is the most promisingrnnew material for high voltage and large current varistors. At present, the SnO2 varistors still have the problems ofrnlarge leakage current and relatively low nonlinear coefficient. For the low leakage current and high nonlinearrncoefficient of the varistors, in this paper, the influence of different amounts of Ni2O3 on the electrical propertiesrnand microstructure of SnO2⋅MnO2⋅ZnO⋅Ta2O5 system was studied. The formation mechanism of the electricalrncharacteristics of SnO2 varistors was studied by measuring current-voltage, SEM, capacitor-voltage, X-rayrndiffraction and ac impedance spectra of the samples. It was found that the electrical characteristics of the samplesrnwere the best (the voltage gradient was 563V/mm, the leakage current was 8.87 μA/cm2, the nonlinear coefrnficient was 38.5), when 0.2 mol % Ni2O3 was added. This study has reference significance for exploring SnO2rnvaristor with high nonlinear and low leakage current.